Noobish question

[Novella1st]

I recently dusted off my old playstation and backed up my copy of Valkyrie profile. Now the backups work just fine, but about halfway through the game you have to change discs, which for the life of my I can't figure out how to get the playstation to recognize the new cd. And yes I've tried booting up with the second cd on it's own and everything seems fine, I just can't figure out how to swap the discs during the game and get it to recognize the 2nd cd.

I'm using one of those gameshark methods where you pop in a boot cd or an old game you don't care about and then swap it out with the backup of the game before you begin playing. Is there a method for getting the playstation to recognize the backup cd 2 during gameplay? I tried browsing the forums, but I didn't see anyone else having a problem like this.